Blackwood was born in Shooter's Hill (today part of south-east London, but then part of northwest Kent) and educated at Wellington College. His father was a Post Office administrator who, according to Peter Penzoldt, ""though not devoid of genuine good-heartedness, had appallingly narrow religious ideas"".Blackwood had a varied career, farming in Canada, operating a hotel, as a newspaper reporter in New York City, and, throughout his adult life, an occasional essayist for various periodicals. In his late thirties, he moved back to England and started to write stories of the superna.